Inflatable therapeutic supports for patients have been well known for many years. Such therapeutic supports include inflatable mattresses and cushions.
Most therapeutic supports are designed to reduce “interface pressures.” Interface pressures are the pressures encountered between the therapeutic support and the skin of a patient positioned on the therapeutic support. It is well known that interface pressures can significantly affect the well-being of immobile patients in that higher interface pressures can (a) reduce local blood circulation, (b) cause bed sores and (c) cause other medical complications. With inflatable mattresses, such interface pressures depend (in part) on the air pressure within the inflatable bladders.
Bladders
Every inflatable therapeutic support has at least one bladder. That bladder has a top surface capable of receiving an object like a patient, a bottom surface that is opposite the top surface, and at least one side surface positioned between the top and bottom surfaces. The bladder surfaces can be a fluid impermeable material, fluid permeable material or combinations thereof depending on the desired application. For example, the bladder material can be a polymeric material, for example, vinyl, polyethylene, polyurethane or combinations thereof. The bladder can be made from a single piece of material or a plurality of materials to obtain the desired results. These various surfaces define a bladder cavity that receives a fluid.
The bladder cavity receives the fluid, normally air or an aqueous solution, through an inlet from a fluid source. The fluid travels from the fluid source through a conduit(s) and the fluid's flow, flow rate, and temperature (those characteristics and others are commonly referred to as therapeutic fluid traits) are normally controlled by a control unit.
The control unit, for example, has a plurality of input keys interconnected to at least a microprocessor. The patient or patient's caregiver essentially controls the therapeutic fluid traits through the input keys. The term input keys means a keyboard system, switches, software chips, levers, dials or any other conventional device that is used as an input device by the patient or patient's caregiver to control the operation of the therapeutic fluid traits.
In the microprocessor embodiment, the microprocessor receives the desired instructions from the input keys. From those instructions, the microprocessor processes those instructions to transmit the desired signals to operate a pump, an air compressor, a heater, a cooler, a fan, valves and/or switches that push, pull and/or allows (by potential energy contained in the bladder(s)) a fluid into, through or to pass into a first conduit(s) to the respective bladder(s) at the desired therapeutic fluid traits. Prior to entering the conduits, the fluid is contained within a heated reservoir, a cooled reservoir, an ambient reservoir, ambient environment and/or combinations thereof; a.k.a., fluid source.
From this fundamental understanding of inflatable bladders, the variations of bladders are evident. For example, some bladders (1) have the inlet removed after the fluid is inserted into the bladder cavity so the bladder is a self-contained, static bladder and (2) retain the inlet so the bladder is a dynamic bladder that can receive and/or release fluid from the bladder cavity.
In the dynamic bladder embodiment, the fluid exits the bladder through at least one outlet. In one version, the fluid exits the outlet (a.k.a., the inlet) through the first conduit to return to the fluid source. In other versions the fluid exits the outlet (not the inlet) through a second conduit to a receiving unit (distinct from the fluid source) or the fluid source. Another version has the surface of the bladder having a plurality of apertures designed to release a portion of the fluid (normally air) toward the object positioned above the inflatable bladder (a.k.a., low-loss bladder). Other outlet versions have combinations of the above-identified outlet versions.
There may be alternative embodiments to these generic descriptions of dynamic bladders and control units. The bladders may have alterations to (1) generate desired fluid flow patterns within the bladder, (2) obtain desired bladder firmness and (3) allow the bladder adaptability for the therapeutic support system. To obtain such results and others like it, the bladders could have predetermined button welds, welds, and slits along welds. Welds are locations where the bladder's top surface is connected to the bladder's bottom surface.
Standard Therapeutic Bladder
One example of a therapeutic patient support system having a therapeutic bladder is disclosed by Hand et al. in expired U.S. Pat. No. 5,606,754. Hand et al. disclose “a . . . patient support system [having] a rigid support frame [and] a plurality of inflatable [bladders] supported upon the support frame with each [bladder] having an upper surface so that the plurality of [bladders form] a patient support surface. The inflatable [bladders] are pressurized and maintained at a predetermined pressure. This predetermined pressure may be a patient height and weight specific pressure profile.” It is known that the bladders can be positioned horizontally (a.k.a., perpendicular to a patient properly positioned on the therapeutic support) and/or vertically (a.k.a., parallel to a patient properly positioned on the therapeutic support) in relation to the support frame. This therapeutic patient support system embodiment utilizes a standard therapeutic fluid bladder.
Wave Therapy
When the bladders on a standard support frame are positioned horizontally, the bladders can be divided into at least two sets (1-2-1-2) to provide wave therapy. Wave therapy is accomplished when (a) the first set of bladders receives fluid and, at the same time, the second set of bladders releases fluid; and then (b) the second set of bladders receives fluid and, at the same time, the first set of bladders releases fluid. That process causes a wave sensation under the patient. The wave therapy can occur with additional sets of bladders, for example “1-2-3-4-1-2-3-4”, “1-3-2-1-3-2” and variations thereof.
The wave therapy, in one embodiment, is accomplished by (a) the first bladder set interconnects to the control unit through a primary first conduit system; and (b) the second bladder set interconnects to the control unit through a secondary first conduit system. To obtain the desired wave therapy, the control unit positions a valve that transmits fluid to either the primary first conduit system or the secondary first conduit system in predetermined time frames to obtain the wave motion. The control unit can also alter the valve so the primary first conduit system and the secondary first conduit system receive fluid simultaneously if no wave therapy is desired.
Turn-Assist Bladder Therapy
Turn-assist bladder therapy is an obvious variation of a rotating bladder therapy. The rotating embodiment is used to decrease sores on immobile patients. An example of a rotating (turn-assist) therapy is disclosed in U.S. Pat. No. 5,794,289 which is commonly assigned and is hereby incorporated by reference.
In U.S. Pat. No. 5,794,289, Gaymar describes a rotating bladder system 10 having upper and lower right side rotating bladder(s) 12a,b and upper and lower left side rotating bladder(s) 14a,b positioned below a surface bladder 180. The rotating bladders rotate a patient positioned on the surface bladder by controlling the air pressure in the right set of rotating bladders and the left set of rotating bladders. The right rotating bladder set is inflated and deflated simultaneously; likewise the left rotating bladder set is inflated and deflated simultaneously. This is accomplished by having the bladders 12a,b interconnected to the control unit 20 through a first conduit 16 and the bladders 14a.b interconnected to the control unit 20 through a second conduit 18 as illustrated in FIGS. 1, 2, and 3.
To rotate a patient 11 to its right side requires decreasing the air pressure in the right set of rotating bladder(s) 12a,b while increasing the air pressure in the left side rotating bladder 14a,b so the left side is higher than the right side as illustrated in FIGS. 1, 2 and 3.
To rotate the patient to the patient's left side requires decreasing the air pressure in the left side rotating bladder(s) 14a,b and increasing the air pressure in the right side rotating bladder 12a,b, so it is opposite of what is illustrated in FIGS. 1, 2 and 3.
The air pressure required to rotate the patient depends on the patient's weight, body type and various other parameters. The quantity of air pressure that rotates one patient, e.g., 30 degrees, may rotate another patient, e.g., 5 degrees. For example, two female patients weigh 130 pounds, one patient is pear-shaped and the other is apple-shaped. The pear-shaped patient rotates 15 degrees with 10 mm Hg while an apple-shaped patient rotates 7 degrees with 10 mm Hg. Obviously each patient is unique and different and the control unit has to be controlled to provide the desired rotation for each patient.
As clearly set forth in Hill-Rom's U.S. patent application publication number 2006/0168736, turn-assist bladders and rotational bladders are essentially synonymous—“a turn-assist cushion or turning bladder or rotational bladder 74 . . . .” If there is a difference between a turn-assist bladder and a rotation bladder, the difference is in the software used in the control unit. In the rotation bladder embodiment, the control unit (1) has the bladders in a set position—planar which can be completely deflated or just partially inflated, (2) rotates the patient, through the bladders, in a first direction by inflating one set of rotating bladders (for example the right set), (3) reverts the bladders to the set position, (4) rotates the patient, through the bladders, in a second direction by inflating the other set of rotating bladders (for example the left set) and (5) reverts to the set position. The turn-assist bladder embodiment, in contrast, eliminates the third step. Accordingly, it seems relatively obvious that the technology for the turn-assist embodiment is an obvious variation of the rotation bladder embodiment by merely altering the software used in the control unit so the bladders are rotated from a first direction to a second direction without the intermediate step of reverting to a set position.
In the prior art and as previously described above, the upper section and the lower section for each right and left set of rotational (or turn-assist) bladders are inflated at the same time to obtain the desired rotation. Moreover, the rotational (or turn-assist) bladders are positioned below other bladders or other cushion materials. See FIG. 11 (rotational bladders 184, 188 are under cushion 180) in U.S. Pat. No. 5,794,289; FIGS. 17 to 19 (rotational bladders 145, 146, 147, 148 are under cushion 182) in U.S. Pat. No. 6,584,628; FIG. 3 (rotational bladders 80 are below cushion 60) in U.S. patent application publication number 2006/0168736; and FIG. 4 (rotational bladders 110 are positioned below cushions 33) in U.S. Pat. No. 6,499,167. In other words, the rotating (turn-assist) bladders are positioned below another cushion which the patient is designed to be positioned upon.
Like the standard bladder therapy system, the rotating bladder therapy system can also provide wave therapy. In most embodiments, the wave therapy, on a rotating bladder therapy system, occurs when (1) the rotating bladders are in the set position—generally planar—and (2) the wave therapy bladders are positioned above the rotating bladders. The wave therapy bladders are not the same as the rotating (turn-assist) bladders. Rotating (turn-assist) bladders do not perform wave therapy. One reason wave therapy is not performed by the rotating bladders is because the rotating bladders are positioned below another bladder.
Software Means to Inhibit Bottoming Out
Programming an air pressure cushion unit requires a skilled technician. The skilled technician analyzes each patient and alters the programming to attain the desired air pressure. One method to avoid the expensive technician's analysis and re-programming is to create a self-monitoring mattress.
Previous self-monitoring air pressure cushions have utilized electrical signal transmission devices and electrical signal receiving devices. In one embodiment, the transmission device is a part of the top surface of a bladder and the receiving device is a part of the bottom surface of the bladder. That means the transmission and receiving devices are separated by a bladder cavity. By monitoring the duration of the signal from the transmitter to the receiver, the operator can monitor the size of the bladder. The size of the bladder corresponds to the air pressure and, it desired, the rotation of the patient. Such signal devices are disclosed in U.S. Pat. No. 5,794,289. Those signal devices generate electrical signals, like rf signals, that may, however, adversely effect other medical equipment. In particular, Wortman et al. disclosed (without reference numbers):
[There] is illustrated an inflatable cushion which is shown to be similar to cushion but may be any other suitable inflatable cushion. The cushion is provided with button welds to prevent ballooning thereof. The cushion has upper and lower surfaces. Cushion inflation is related to the distance between the upper and lower surfaces.
In order to prevent bottoming-out from occurring and to more precisely regulate the cushion inflation, the cushion is inflated so that the distance between the upper and lower surfaces is a predetermined distance. A transmitter coil and a receiver coil are provided adjacent the upper and lower surfaces, and the distance there between is related to the signal strength of a signal transmitted there between. Alternatively, the coil may be provided adjacent the lower surface, and the coil provided adjacent the upper surface.
In any case, those Gaymar patents illustrate that controlling the air in a cushion is desirable to prevent bottoming and prevent excess pressure being applied to the patient. “Bottoming” refers to any state where the upper surface of any given cushion is depressed to a point that it contacts the lower surface, thereby markedly increasing the interface pressure where the two surfaces contact each other. Prior to bottoming occurring, the pressure exerted by the bladder on the skin of the object becomes excessive. Those bottoming sensors are acceptable but Gaymar has been seeking to improve such sensors and/or eliminate them. The improvements are made for numerous reasons. Some of these reasons are and not limited to cost, reliability, easiness or difficulty to install and adjust the system, and simplicity. In addition, the bottoming sensor should be able to diminish the chance of bottoming out and also decrease the chance that the cushion will exert too much pressure to the patient.
Currently, rotating bladders are positioned below other bladders. That “other bladder over the rotating bladder” embodiment decreases the rotating bladders' efficiency of providing the desired rotation therapy. Merely removing the other bladder causes other problems for example bottoming out. The bottoming out problem with rotating bladders has been previously discussed above. The bottoming out issue remains a problem when the other bladders are removed to maximize the rotating bladder's therapy efficiency. Moreover, positioning bladders or other resilient materials (foam or gelastic material) below the rotating bladders is not desired because the rotating bladders are positioned over a non-secure, non-rigid material.
Foam Filled Bladder
A different bladder embodiment is disclosed by Stryker's U.S. Pat. No. 5,325,551. In the '551 patent, Stryker disclosed a bladder completely filled with foam having apertures and the air circulates through those apertures. Stryker wrote (without reference numbers), “An inflatable air bladder of generally rectangular shape rests on the bottom sheet between the side elements [of a mattress] so that three sides of the air bladder engage the respectively concave surfaces [of the mattress]. The vertical thickness of the air bladder is substantially equal to the vertical thicknesses of side elements and head element [of the mattress]. The end of the air bladder remote from element is approximately flushly aligned with the adjacent end surfaces of the side elements. The internal construction of the air bladder is described in more detail later. Two air hoses each communicate with the interior of the air bladder at opposite corners of the end nearest the foot end of the mattress. The air hoses have at the outer ends thereof respective conventional connector elements . . . . The foam elements are somewhat stiffer than the pressurized bladder, and thus serve as a frame which helps to keep a patient centered on the bladder. Also, after giving a hypodermic injection, hospital personnel sometimes insert the needle temporarily into a mattress while completing other tasks. In the preferred embodiment, the six inch horizontal width of foam elements and the two inch vertical thickness of foam sheets [positioned over the bladders] protect against puncture of the bladder in the event a hypodermic needle is inserted into the mattress unit . . . . The air bladder is filled by a foam sheet which is of generally rectangular shape. In the preferred embodiment, the foam sheet has an ILD for the foam material itself which is less than 15 lbs. The foam sheet has above it an upper sheet and has below it a lower sheet. In the preferred embodiment, the [foam] sheets are made of polyurethane-coated nylon. The [foam] sheets are bonded in a conventional manner to the surfaces of the foam core, and along the peripheral edges of the foam core the [foam] sheets are bonded to each other in a conventional manner . . . . The foam core has a plurality of horizontal cylindrical holes extending transversely therethrough. The holes soften the [foam] sheet, and also facilitate rapid air movement within the bladder so that pressure equilibrium is quickly restored after a change. It should be noted that the spacing between adjacent holes is, for the four holes at the head end of the bladder and the three holes at the opposite end, approximately half the spacing between adjacent holes in the center region of the bladder. The holes increase the softness of the air bladder, and in particular can be used to give the foam sheet an effective ILD value which is less than the rated ILD value of the material of the foam sheet when no holes are present, and in fact the provision of holes allows the foam sheet to be given an effective ILD value which is less than the lowest ILD foam material readily available on the commercial market. By varying the spacing between adjacent holes in different portions of the foam sheet . . . respective portions of the foam sheet can be given different effective ILD values. In the preferred embodiment, the holes are all of uniform diameter and the spacing between adjacent holes is varied, but it will be recognized that an equivalent result can be achieved by varying the diameters of the holes while maintaining a uniform spacing between adjacent holes, or by varying both the diameters and the spacing. Also, of course, the effective ILD of the foam can be relatively uniformly reduced by using uniformly spaced holes of equal diameter. The result is that different portions of the bladder will exhibit different stiffness properties even though the same air pressure is present throughout the bladder.” (Bolded words for emphasis.) A problem with that embodiment is that the foam is really the cushion material, not the air in the bladder. It is preferred that the fluid in the air bladder be the principal source of pressure applied to the patient, not the foam. Moreover, a bladder filled with foam is unable to be a rotating bladder or a wave bladder since the foam does not expand with air.
Air Bladder and Gel Material Cushion
In U.S. Pat. No. 6,554,785; Sroufe et al. wrote, “An orthopedic device of a therapeutic nature which includes an air bladder and an overlying gel bladder. The air and gel bladders are joined and are secured within a retainer which is adapted to be placed about a body part of a patient with the air or gel bladder being positioned next to the body part.” The gel bladder is positioned over the air bladder so the gel bladder is the principal bladder that contacts the patient.
In U.S. Pat. No. 6,306,112; Bird wrote, “A therapeutic ankle support brace bladder pad member having a pair opposed surfaces defining an inflated air support pocket and a second support pocket containing gel material and filler apparatus materials, is disclosed. An overlay fabric material is integrally attached to the bladder, provides additional support and enables removable attachment of the bladder to side support members of a therapeutic brace.” That means the air bladder contacts first portion of a patient and gel bladder contacts a second portion of the patient.
In U.S. Pat. Nos. 6,306,112 and 6,554,785, the inventors fail to disclose a dynamic air bladder or a resilient member in a dynamic air bladder or equivalents thereof. Instead the inventors concentrate on applying the desired gel cushion characteristics to one part of a patient's body and air cushion characteristics to a second part of a patient's body.
Those problems are solved by the current invention that is disclosed in the present application.